#include <stdio.h>

int main () {
	char c;scanf("%c",&c);
	printf(((c>='A'&&c<='Z')?"%c\n":"Error!\n"),c-'A'+'a');
	scanf(" %c",&c);
	printf(((c>='a'&&c<='z')?"%c\n":"Error!\n"),c-'a'+'A');
	return 0;
} 
